By ESPNSTAR.com staff
Victor Wanyama and Tony Watt helped Celtic record the famous victory a day after their 125th anniversary at Parkhead despite being overwhelmed by Barcelona, who dominated possession in the match.
Messi's injury time strike was not enough to rescue Barcelona and the Argentine felt that an unfortunate combination of missed chances, the woodwork and another inspired performance from goalkeeper Fraser Forster cost his side the game.
"We did everything well, played better than two weeks ago against them, but the ball didn't go in," he said after the match.
"The same thing happened at the Camp Nou. They played defensively and they waited to make fast counterattacks. They are very comfortable on corners and set-pieces, and that's how they scored their two goals."
Messi celebrated the consolation goal with a thumb-sucking gesture as a tribute to his new-born son Thiago and he hopes that there will be more opportunities for that celebration.
"In the end, the goal didn't mean anything, the game was already lost. There are enough games left to dedicate goals to Thiago," he added.
Barcelona now lead the group with nine points but will need to win their next match against Spartak Moscow to guarantee qualification while Celtic are second with seven points.